SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0680760014d0580058e6d471737e414060989f0f3b0ee4ed72b384666eb6e2d0' 
  AND token = 'NtP3L78WjVqmZNVvEIZFhpqCNg7SMtoXOhB+lKiPLe4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}